The penis

Penis, willy, prick, balls, lingam... All over the world there are many words for this thing hanging between the legs of half the population. But how does it function? How come it’s not always hanging? And what does a penis look like inside?

Here it is, the willy. Closest to the body, hangs the scrotum, and inside it there are two testicles. Here is the shaft of the penis. Inside the shaft is the urethra, which the pee runs through. And at the end is the glans.

This is very sensitive to touch, and it usually feels pleasant to stroke it. Another very sensitive part of the penis is this fold of skin, on the lower side of the glans. It is the frenulum. Around the glans, there is a layer of skin, the foreskin. White spots, or bumps form here.

They are sebaceous glands, which protect the skin from irritation and infection. This penis does not have a foreskin. In many cultures it is common that boys have parts of their foreskin cut off. This is called circumcision. When circumcised the penis develops a thicker skin and therefore the glans becomes less sensitive.

Penises look different from person to person, just like faces. They have much, little or no foreskin. They vary in colour and shape, and they point in different directions. It is not unusual to worry about the appearance of the penis. “Does it look the way it should? Is it large enough?

Will it be pleasing for a partner in sex?” The answer is: Yes, it will. And yes, it is large enough. Many think that the size of the penis plays a role in how nice it is to have sex. But there are other things which are a lot more important: like whether you and your partner really listen to each other, and are aware of what you both prefer. But, let’s go back to the testicles.

Here, cells called sperm are formed, that can combine with an egg and develop into a brand new human being. In a testicle, several million sperm are formed every day. They are pushed through these passages, the vas deferens, to a gland called the prostate. Here, the sperm are blended with prostate fluid. In the seminal vesicle, another fluid is produced.

The fluid from the seminal vesicle is mixed with the sperm from the testicles, and with the prostate fluid. Together, it becomes semen. Or seminal fluid. Usually, the penis is soft, and the skin is loose. But when you become sexually aroused, horny, something happens to the penis.

Inside it, there are three chambers that begin filling with blood. The penis grows, and gets hard and erect. It is called an erection, or a hard on. Usually you get a hard on because you see or think of something, or someone, who turns you on. Or by someone touching you in a nice way.

But you can get a hard on anyway, whenever. Often, you have it when you wake up in the morning. Other times, you can get a hard on from the vibrations on a bus. Sometimes it seems as if the penis has a mind of its own. When you masturbate, or have sex some other way, an excitement rises in the body.

You are stimulated. When you are sufficiently stimulated, the muscles around the penis start contracting, in rhythmic motions. The movement pushes the seminal fluid out through the urethra. It can spurt quite a long way, or ooze out, or come in small squirts. This is called an ejaculation.

The amount of seminal fluid is usually between one or two tea spoons, and it can contain hundreds of millions of sperm. Ejaculation often happens as the sexual pleasure reaches its peak, the orgasm, but ejaculation and orgasm are not the same thing. You can ejaculate without having an orgasm, and you can have an orgasm without ejaculation. After the ejaculation, the penis relaxes. The chambers are emptied of blood, and the penis gets soft again.

Until you get horny the next time. Sometimes you can ejaculate while asleep, without being able to control it yourself. Such an unintended ejaculation while asleep is called a nocturnal emission. This is a way for the body to get rid of older sperm and make room for new. Anyone who ejaculates often, for example by masturbating, usually doesn’t experience nocturnal emissions.

Well, that’s how a penis functions. But how yours functions best, or your partner’s, and what feels nicest: that you’ll have to find out for yourselves.